The purpose of this study was to examine the sensitivity, reliability, and concurrent validity of the Patient-rated Forearm Evaluation Questionnaire (PRFEQ). Reliability on three consecutive days was evaluated with 22 of 94 subjects who had chronic lateral epicondylitis (LE) and who concomitantly participated in an outcome study. The PRFEQ results were compared with results of the Visual Analogue Scale; the Disabilities of the Arm, Shoulder, and Hand questionnaire; the Medical Outcomes Study 36-Item Short Form Health Survey; and the pain-free grip strength measurement. Questionnaires were completed at baseline, six weeks, and 12 weeks. Reliability was excellent using variance components and interclass correlation coefficients (PRFEQ function subscale, 0.92; PRFEQ pain subscale, 0.96; PRFEQ total scale, 0.96). Generally, correlations were moderate between the PRFEQ subscales and total scale and the other outcome scales. Effect size and standardized response mean were good in many outcome scales, being slightly higher in the PRFEQ than in the other outcome measures. The PRFEQ is reliable, reproducible, and sensitive for assessment of LE. It is at least as sensitive to change as the other outcome tools tested. The PRFEQ should be a standard primary outcome measure in LE research.